The original Browning Automatic Rifle was developed for the US Army during World War 1 to replace the French Chauchat and Hotchkiss M1909 Benet-Mercie light machine guns. Design work under John Browning's direction began in 1917 to which the rifles were in circulation in 1918 and saw limited exposure during the war. The BAR was born of the growing concept concerning arming the regular infantryman with a portable automatic weapon capable of voluminous fire. Such a weapon was deemed appropriate considering the fixed nature of trench warfare during the conflict where the reach of bolt-action types proved limiting. Some 100,000 BARs were ultimately produced through a bevy of select manufacturers (including Colt and Winchester) from 1917 into the 1950s and these examples went on to see combat throughout World War 2, the 2nd Sino-Japanese War, the Korean War, the Vietnam War and even as recently as the Palestinian Civil War of 2006-2011.
Within time, the Colt Patent Firearms Mfg Company took their BAR to the civilian market under the name of "Automatic Machine Rifle" Model 1919 (AMR M1919) and this graduated to become a 1924 upgrade and a follow-up 1925 upgrade known as the "Model 1925". It was the 1925 variant that would serve as the basis for a new Belgian light automatic weapon under the FN Herstal brand production label. License-production of the Colt M1925 allowed the famous BAR to be adopted by the Belgian Army service as the FN Mle 1930 (or "Fusil Automatique Modele 1930").
While largely respectful of its American BAR origins, the Mle 1930 incorporated some changes to suit Belgian Army requirements. This included a revised magazine case, a heavy-duty barrel assembly, a carrying handle, a new gas cylinder regulator, new ejection port covers and a folding bipod. One key defining physical feature of the Belgian version was the rather novel ribbed section of barrel intended to counter the effects of heat build up along the assembly during sustained fire. However, the actual value of this design addition was somewhat doubtful and more akin to World War 1/post-war machine guns. The weapon was primarily chambered for the standard Belgian 7.65mm cartridge of the period though other chamberings would eventually appear due it being offered commercially.
The Mle 1930 enjoyed a relatively favorable presence in the world market as variants were sold to overseas places like China, Poland and Chile. The Mle 1930 series was eventually modernized prior to World War 2 in 1932 to become the "Mle Type D" incorporating a much-needed "quick-change" barrel function and simplified receiver and went on to be chambered for the larger-caliber 7.92x57mm Belgian Mauser cartridge. In the post-war years, it was adapted further to make use of the .30-06 Springfield and NATO-standard 7.62x51mm cartridge in keeping up with changing battlefield requirements.
At any rate, the Mle 1930 was a respected and serviceable weapon though it did retain the key limitations of the original American BAR design of 1918 - it was relatively expensive to produce in the numbers required and was tactically limited by its 20-round box magazine. By the 1960s and 1970s, there proved vastly superior options available on the world stage and the Belgian BAR fell to disuse.